My garage is at the end of the garden - a concrete pre-fab one. It is
accessed by a dead end road shared between me and my neighbours. At
the garage door end there is a 4' -6' gap to my garden boundary which
joins the end of the road.


I would like to extend the garage the 4' or so so i can 'use' the 6' x
4-6' area at the end of the garage that is otherwise wasted really.

I was going to do this simply using breezeblocks and a new door. Do I
need planning permission for this? The garage is on the house plans
but the detail (or lack of) mean you would struggle to tell the length
of the garage or where is was located i.e. if the 4-6' gap is at the
end of the garage, no gap at all or at the other end.

If planning permission is required what sort of things would it
require - would these be restrictive for a DIYer on his own to build?
Would planning permission (for the extension) require modifications to
the existing garage?

What would the planning permission cost?